In the production and development of biopolymers including proteins, liquid chromatography is frequently used for adsorbing, separating, or purifying the biopolymers. Known carriers for use in separating medium for liquid chromatography include inorganic carriers such as silica gel and hydroxyapatite, natural polymeric carriers such as agarose, dextran, cellulose, and chitosan, and synthetic polymeric carriers such as polystyrene and poly(meth)acrylic esters. These carriers are used as such or used after various functional groups are imparted thereto according to need in order to render the carriers usable in a variety of separation modes.
Recently, many proposals have been made on epoxy-resin-based carriers for use as separating medium for liquid chromatography, from the standpoints of impact resistance, chemical resistance, durability, handleability, production efficiency, etc.
Patent Document 1 proposes a porous cured epoxy resin object usable as the carrier of an affinity gel or as a purifying medium, absorbing/adsorbing medium, packing material for column chromatography, etc. This porous cured epoxy resin object is a porous object which has voids communicating with the three-dimensional network backbone of the cured epoxy resin and in which the three-dimensional network backbone constitutes the porous object, which is of a non-particle-aggregation type configured of columnar three-dimensional branched structures. In this porous object, the proportion of aromatic-ring-derived carbon atoms to all the carbon atoms constituting the cured epoxy resin is 0.10 to 0.65. Furthermore, this porous object has a porosity of 20 to 80% and an average pore diameter of 0.5 to 50 μm. Although Patent Document 1 indicates that the porous cured epoxy resin object can have any shape such as a sheet shape, rod shape, or cylindrical shape, there is no mention of particulate shape therein.
Patent Document 2 proposes a porous object suitable for use as, for example, a separating medium for chromatography, porous object for blood separation, sample concentration medium for environmental analysis, porous object for moisture absorption, porous object for adsorbing low-molecular-weight substances for the purpose of deodorization, etc., porous membrane for use in a membrane emulsification method for producing fine particles with an even diameter, or porous object for use as an enzyme carrier or catalyst carrier. This porous object has a three-dimensional network structure backbone constituted of a cured epoxy resin and has voids, and the backbone has mesopores therein having a pore diameter of 1 nm to 1 μm. Patent Document 2 also indicates that the porous object can be easily made to have any shape such as a sheet shape, rod shape, or cylindrical shape. However, Patent Document 2 includes no mention of particulate shape.
Patent Document 3 proposes a porous cured epoxy resin object which is a cured epoxy resin of a porous structure obtained by heating a liquid mixture including an alicyclic epoxy compound having three or more epoxy groups in the molecule, an alicyclic amine hardener, and a solvent inert to both the alicyclic epoxy compound and the alicyclic amine hardener to obtain a cured object and then removing the solvent from the cured object. Patent Document 3 also indicates that the porous object may have a shape such as a sheet shape, rod shape, or cylindrical shape, but there is no mention of particulate shape therein.
Patent Document 4 proposes a process for producing a porous cured epoxy resin object, wherein a liquid mixture including an epoxy resin (component A), an amine hardener (component B), and a solvent (component C) inert to the components A and B is heated under the temperature conditions of 30-55° C. for 6 hours or longer to obtain a cured object and the component C is then removed from the cured object to obtain the porous cured epoxy resin object. Patent Document 4 also merely indicates that the porous object to be produced can have any shape such as a sheet shape, rod shape, or cylindrical shape, and there is no mention of particulate shape therein.
Patent Document 5 discloses porous spherical epoxy-based particles obtained by adding a water soluble amine based compound to an epoxy compound emulsion containing, dissolved therein, a compound which is compatible with the epoxy compound and is extractable or volatilizable, thereby producing cured spherical epoxy particles, and removing the extractable or volatilizable compound from these particles by extraction or volatilization.